Position and force feedback are crucial requirements for high performance industrial and consumer based control applications. Such applications include micro and nano positioning, human interactive robotics, multi-agent robotics, toys, soft tissue handling and animatronics.
Traditional transducers include AC and DC motors, pneumatic, solenoid and hydraulic actuators. Sensory feedback from traditional transducers is commonly provided by additional components such as strain gages, accelerometers, laser interferometers, encoders, potentiometers, LVDTs, pressure sensors, load cells, and additional electroactive sensors. Each of these components requires extra power and signal recovery circuitry. Furthermore, in space critical applications, the additional components commonly used to provide sensory feedback can interfere with the motion of the transducer and inhibit adequate operation of the device.
Active material based transducers are an alternative to the traditional transducers outlined above. Active material based transducers provide compact architectures for applications with limited space. In particular, electroactive polymers are active materials that commonly demonstrate high strain capability at lower pressures than piezoceramic or magnetostrictive transducers. Therefore, such materials are especially suitable for large strain applications such as those listed above. In applications involving electroactive polymer transducers, the traditional approach to obtaining sensory feedback by addition of sensory components is cumbersome and with large strain transducers some methods of obtaining feedback are seemingly impossible to implement. Furthermore, the addition of sensory elements to the transducer compromises the compact quality of electroactive polymer based devices that primarily attracts designers to these materials.
In view of the foregoing, an alternative, cost effective and compact electroactive polymer based transducer is desirable. Further, an electroactive polymer based transducer for the inline sensing of strain, pressure, and health monitoring for electroactive polymer based transducers is also desirable.